HELP - My battery keeps going flat!

[Martyn]

A month ago, I returned to my car after a week of not driving it to find that the battery was completely flat. Slight problem because it has a Clifford 500 alarm and it's been de-locked, so I had to call the AA to get them to break into the car for me. They charged the battery, and it was fine until it was left for a few days and then the same thing happened again.

My local mechanic tested the drain on the battery and it's draining at a rate of 200mA. I was led to believe that that's acceptable. Is that true, or do I have excessive battery drain there?

The alternator is fine and kicks out 14.7A. I suppose it could be that my battery is knackered, but does anyone have any other ideas before I replace it? Specifically I'd like to know if 200mA is too much of a drain on a battery. The guy from the AA seemed to think that anywhere from 0.2-0.5A is normal, but I don't always believe what they say (although this guy seemed pretty sound).

I do have some pretty heavy duty amplifiers in the car and a power tap, however the power tap does "shut down" after a few minutes as it should do, and the amps aren't on when the ignition isn't on, so I don't think that's the problem. The power tap is necessary because my bass amp draws over 60A when it's running at full power

Please help if you can

[Jonty]

To start off with some basics, how old is the battery..? If it's around 4-5 years old then I expect it's showing signs of wanting to visit battery heaven, or 'hell' if it stranded you outside of a de-locked car.

Does it require maintenance (i.e. topping up with distilled water) or is it a maintenance free battery..? If your alternator is fine then I suspect the battery is failing. Also, it's been known that some 'healthy' batteries can fail if they're allowed to run right down... to a point where they may not recover.

Testing a battery with a voltmeter won't help much to be honest, neither will an ammeter reading. If you can leave the battery on charge, run it for a while and then it dies within a few days then I'd replace the battery. If your ICE install worked fine before then it's probably further proof of a failing battery, or have you installed something new recently..?

You can pick up a standard battery from Halfords for £50, or £60-70 for one of their Calcium, maintenance-free ones.

Hope this helps.

Jonts.

[Martyn]

Thanks for the reply,

My problem is I've only had the car just over 6 weeks, so I don't really know it's history that much. I contacted the previous owner last night and he said it had a relatively new battery in there. He also said that he used the car regularly (like every day), so he didn't experience the problem.

I'm beginning to think that the Clifford Concept 500 alarm is draining too much of the battery and therefore flattening it after a few days. I've seen reports of other alarms doing a similar thing because they are contantly monitoring for intrutions. It seems strange to me though, because if you were going on holiday for any lengthy period of time, you'd want the alarm to be operative all the time, not just for the first couple of days.

In any case, the battery is still being drained at a rate of 200mA, and I've been told now by my mechanic's friend that a rate of 50mA is quite high, and 20mA is normal.

[Jonty]

Hi Martyn.

Call it a conspiracy theory but if I was the seller and someone called me up to question whether the battery was a bit dicky then I too would say it was "okay" if I'd sold the car knowing it wasn't. Not that I would, but you can see where I'm coming from. That aside, personally I'd want to make sure I could vouch for the battery after buying a car and if a receipt couldn't give me an indication of what to expect then I'd rather cough up some beer tokens and replace it. The old one can always be used as a handy spare.

If we go with the assumption that the battery is fine but something is drawing too much current, think about what's in the car that could be doing it. Personally I think you can forget about the alarm as long as it was installed by an approved fitter. I have a Clifford system (with a few added toys) and I can leave my car alone for a couple of weeks before I'll have trouble starting it.

I wonder whether there's an ICE component which is drawing power when it shouldn't be..? If the car is regularly left standing then pull the fuse for the amp and see if that makes a difference. Either/or, pull the plug for the head-unit and test that theory too. If you do this and there's still no change then at least you can rule them out.

Can we also assume you're not leaving your lights on..?

Regards,

Jonty.

[Martyn]

Well yes, I do see where you're coming from regarding the previous owner claiming he didn't have any problems - I have no reason to doubt his sincerety though, as he loved the car and really didn't want to sell it. I tend to believe that he didn't know he had a problem since he used the car on a daily basis, and therefore the battery never went flat.

The alarm was installed by an authorised centre, although I'm not sure where. I have seen the receipt and certificate for it though, I just don't remember the name of the garage. I can't discount a problem with the alarm I think, since I've heard that alarms with movement sensors, proximity sensors and all the other bells and whistles do drain the battery, and of course sirens which have their own battery backup - as this one does.

The two amps in the car have power lights on them, which extinguish when the ignition is turned off, plus the head unit powers down correctly, so I don't think it's them causing the problem. I guess I'll have to start pulling fuses as you suggest to track down the problem. I have a problem doing that with the alarm though since it's tapped into so many systems. I believe there are 7 fuses alone for the alarm which I can see, and possibly more hidden away behind the dash somewhere.

And errr... no, I'm not leaving the lights on

[philz]

It'll probably be the Clifford LED that's draining it, mine certainly does.

I have almost identical ICE and alarm to you and if I arm my car the battery goes flat after a week or so, if I leave the Clifford off it lasts months.

[Martyn]

Ahhh... this is slightly different then, because my battery goes dead even if I don't set the alarm.

[Lylos]

martyn,

Ive just noticed your post after posting pretty much the same thing - im too lazy to look!

Anyway, did you find out what the problem was? I have a toad alarm and it does have a small LED but surely this cant be seeping the life out of my whole car and its been fine in the past. I have had my alternator replaced recently and i doubt its that.

When i indicate right it goes at about 100 bpm, do you think this could be causing the problem, or a fuse....mmm

[Phil Dawson]

martyn,

Ive just noticed your post after posting pretty much the same thing - im too lazy to look!

Anyway, did you find out what the problem was? I have a toad alarm and it does have a small LED but surely this cant be seeping the life out of my whole car and its been fine in the past. I have had my alternator replaced recently and i doubt its that.

When i indicate right it goes at about 100 bpm, do you think this could be causing the problem, or a fuse....mmm

Rapidly flashing indicators usually means one of the bulbs is gone, or perhaps a break in the circuit due to a fuse.

[jimi]

200mA is slightly high but not excessive, mine is about 120mA. You'll find that the clock, radio and alarm all draw power with the ignition off (they have to maintain the settings) also there is very little difference with the alarm armed or not (at least with mine, an Autowatch). Its easy enough to work out (if you know the capacity of the battery in Amp hours) approximately how long a 200mA load will take to flatten the battery. That kind of load shouldn't flatten a good battery in a few days, more like 3 weeks. If its going flat in a few days its probably the battery, get it load tested and you will soon find out. The other thing to consider is your alternator charging properly ? it may not be fully charging your battery, what voltage do you have when the engine is running, should be at least 14.6v